Miniature telephoto lens module and a camera utilizing such a lens module
The presently disclosed subject matter includes a mobile electronic comprising an integrated camera, comprising a Wide camera unit comprising a Wide lens unit, and a Telephoto camera unit comprising a telephoto lens unit, the telephoto lens unit and the wide lens unit having respectively TTL/EFL ratios smaller and larger than 1 and defining separate telephoto and wide optical paths.
1. A mobile electronic device comprising an integrated camera, wherein the camera comprises a Wide camera unit comprising a Wide lens unit and a Telephoto camera unit comprising a Telephoto lens unit, the Telephoto lens unit and the Wide lens unit having, respectively, total track length (TTL)/effective focal length (EFL) ratios smaller and larger than 1 and defining separate Telephoto and Wide optical paths, wherein the Telephoto lens unit comprises multiple lens elements made of at least two different polymer materials having different Abbe numbers, wherein the multiple lens elements comprise a first group of at least three lens elements configured to form a telephoto lens assembly and a second group of at least two lens elements, the second group of at least two lens elements spaced apart from the first group of at least three lens elements by a predetermined effective gap equal to or larger than ⅕ of the TTL of the Telephoto lens unit, wherein the first group of at least three lens elements comprises, in order from an object plane to an image plane along an optical axis of the Telephoto lens unit, a first lens element having positive optical power and a pair of second and third lens elements having together negative optical power such that the Telephoto lens assembly provides a Telephoto optical effect of the Telephoto lens unit and such that the second and third lens elements are each made of one of the at least two different polymer materials having a different Abbe number for reducing chromatic aberrations of the Telephoto lens, wherein the second group of lens elements includes a fourth lens element and a fifth lens element made of the different polymer materials having different Abbe numbers and is configured to correct a field curvature and to compensate for residual chromatic aberrations of the Telephoto lens assembly dispersed during light passage through the effective gap between the Telephoto lens assembly and the second group of at least two lens elements, and wherein the first, third and fifth lens elements have each an Abbe number greater than 50 and the second and fourth lens elements have each an Abbe number smaller than 30.
2. The mobile electronic device of claim 1 , wherein light receiving outer surfaces of the Wide and Telephoto lens units are located substantially in the same plane, thereby reducing shadowing and light blocking effects therebetween.
3. The mobile electronic device of claim 1 , wherein the Wide and Telephoto camera units are mounted on separate printed circuit boards.
4. The mobile electronic device of claim 3 , wherein the printed circuit boards are located in different spaced-apart substantially parallel planes.
5. The mobile electronic device of claim 1 , wherein the Wide and Telephoto camera units are mounted directly on a single printed circuit board.
6. The mobile electronic device of claim 1 , wherein the Wide and Telephoto camera units are spaced from one another a distance d of about 1 mm.
7. The mobile electronic device of claim 1 , wherein the Telephoto lens unit has a TTL less than 6.5 mm.
8. The mobile electronic device of claim 1 , wherein the lens elements of the second group of lens elements are spaced from one another an effective air gap smaller than 1/50 of the TTL of the Telephoto lens unit.
9. The mobile electronic device of claim 1 , wherein the Telephoto lens unit has a TTL smaller than 5.5 mm, an EFL larger than 5.9 mm, and an optical diameter smaller than 4 mm, enabling to provide an image on an entire area of a ¼″ to ⅓″ image sensor.
10. The mobile electronic device of claim 1 , wherein the Telephoto lens unit has a TTL smaller than 6.2 mm, an EFL larger than 6.8 mm, and an optical diameter smaller than 5 mm, enabling to provide an image on an entire area of a ¼″ to ⅓″ image sensor.
11. The mobile electronic device of claim 1 , wherein the Telephoto lens unit TTL/EFL ratio is smaller than 0.9.
12. The mobile electronic device of claim 1 , wherein the Telephoto lens unit TTL is less than 5.5 mm.
13. The mobile electronic device of claim 1 , wherein the Telephoto lens unit EFL is greater than 5.9 mm.
14. The mobile electronic device of claim 1 , wherein the Telephoto lens unit EFL is greater than 6.8 mm.
15. The mobile electronic device of claim 1 , wherein the Telephoto camera unit includes an image sensor and wherein an image captured by the Telephoto camera unit has a field of view that is no larger than 44 degrees.
16. The mobile electronic device of claim 11 , wherein the Telephoto lens unit EFL is greater than 5.9 mm.
17. The mobile electronic device of claim 11 , wherein the Telephoto lens unit EFL is greater than 6.8 mm.
18. The mobile electronic device of claim 1 , wherein the Telephoto lens unit has an F# smaller than 3.2 and a TTL smaller than 6.2 mm.
19. The mobile electronic device of claim 1 , wherein the first lens element of the Telephoto lens unit has a focal length f 1 smaller than TTL/2.
20. The mobile electronic device of claim 1 , wherein the first, second and third lens elements have respective focal lengths f 1 , f 2 and f 3 , and wherein the respective focal lengths satisfy the condition 1.2|f 3 |>|f 2 |>1.5f 1 and wherein the Telephoto lens unit has an F# smaller than 3.2, wherein the Telephoto lens unit TTL is smaller than 6.2 mm.
21. The mobile electronic device of claim 1 , wherein the Telephoto camera unit includes an image sensor with an image sensor size ¼″ or ⅓″.
22. The mobile electronic device of claim 18 , wherein the first lens element of the Telephoto lens unit has a focal length f 1 smaller than TTL/2.